Normally, automatic car couplers that are used on mass and/or rapid transit vehicles permit the effective mechanical coupling and uncoupling of adjacent vehicles and also allow the efficacious connection and disconnection of the electrical trainline and the pneumatic pressure brake line or pipe of the consist of a train. During an uncoupling operation, it is essential to electrically disconnect the trainline circuit contacts and to close or shut off the air pressure in the brake line before the actual physical separation of the cars takes place. In order to protect the electrical circuitry from being damaged and to prevent the air pressure from escaping to atmosphere, it is necessary to quickly open the multi-contact blocks carried by the coupler heads and to rapidly close a pneumatic shut-off valve also carried by the heads of the couplers. Thus, during an uncoupling operation, it is desirable to open the electrical contacts in order to minimize pitting or erosion due to arcing and to preserve fluid pressure for the purpose of centering the detached couplers on the respective cars. Further, it is highly desirable to be able to manually override the centering feature so that the couplers may be skewed to permit coupling on a turn or bend. In addition, it is necessary to convey air under pressure to the oncoming railway car so that the brake pipe and brake cylinders may be properly charged to effect appropriate braking operation upon request of the operator or engineer of the train. Moreover, the pneumatic centering devices must be automatically disabled so that the coupler of each of the coupled cars may freely move its axis of rotation as the train negotiates the bends or curves and the grade in the trackway.